Muffler



R. W. MYERS Aug. 8, 1961 MUFFLER Filed Oct. 1, 1959 IN VEN TOR. R y

W. M 381's ATTORNEYS United States Patent 2,995,199 MUFFLER Roy W.Myers, 116 E. 5th St., Uhrichsville, Ohio Filed Oct. 1, 1959, Ser. No.843,797 6 Claims. (Cl. 181-42) The invention relates to mufilers forinternal combustion engines and more particularly to a mufflerespecially adapted for use upon trucks and the like.

It is an object of the invention to provide a mufiler of this characterhaving an expansion barrel lined with expanded sheet metal for thepurpose of breaking up the sound.

Another object of the invention is to provide such a mufller in whichthe expansion barrel is lined with tubes formed of expanded sheet metal,opposite ends of each tube being flared outwardly forming annularflanges for contact with the interior of the expansion barrel.

A further object of the invention is to provide such a mufller in whichalternate sections of the expanded metal are so arranged that theangular web portions of the expanded metal are alternately located inopposite directions.

A still further object of the invention is to provide a mufiler of thecharacter referred to in which a plurality of concentric tubes ofexpanded sheet metal are located one within the other, wtihin theexpansion barrel of the muffler.

Also, it is an object of the invention to provide a muffier of this typein which a smaller diameter inlet pipe, connected to the exhaust pipe ofthe motor, enters the inlet end of the expansion barrel.

A further object is to provide such a mufller in which means is providedat the inlet end of the expansion barrel for releasing back pressurewithin the expansion barrel and for drawing atmospheric air therein.

The above objects together with others, which will be apparent from thedrawing and following description, or which may be later referred to,may be attained by constructing the improved muffler in the mannerhereinafter described in detail and illustrated in the accompanyingdrawing.

In general terms, the invention may be briefly described as comprising amuffler having an expansion barrel open at its discharge end and closedat its inlet end, excepting for a smaller diameter inlet pipe adapted tobe connected to the exhaust side of the motor.

Means is provided at the inlet to the expension barrel of the muffler,and surrounding the inlet pipe thereto, provding for the release of backpressure within the expansion barrel and for drawing atmospheric airinto the same.

For the purpose of breaking up sound, the interior of the expansionbarrel is lined with expanded sheet metal. This expanded sheet metallining is preferably formed in a plurality of sections so arranged thatthe angular web portions of the expanded metal are alternately locatedin opposite directions.

The expanded metal is preferably formed into tubes, the ends of whichare flared outwardly to form annular flanges for contact with theinterior of the expansion barrel of the mufiler. In order to increasethe eifectiveness of the mufller, two or more tubes of expanded sheetmetal may be inserted, one within the other, to provide a lining for theexpansion barrel.

The means for releasing back pressure and admitting atmospheric air atthe inlet end of the expansion barrel, may be formed by providing arearwardly or downwardly disposed tubular neck at the inlet end of theexpansion barrel, surrounding and of greater diameter than the inletpipe.

This tube is surrounded by a second tube, of larger diameter, closed atits rear or lower end and connected to the inlet pipe and open at itsupper or forward end. This provides a tortuous path through which backpressure may be discharged or released and through which atmospheric airmay be drawn into the inlet end of the expansion barrel. The tubularmembers forming this inlet portion of the muffler may be lined withexpanded sheet metal.

A rearwardly disposed elbow is provided at the upper end of theexpansion barrel, said elbow having a longitudinally disposed slot inits underside to relieve back pressure in this end of the barrel. One ormore layers of expanded sheet metal may be located around the interiorof the elbow.

Having thus briefly described the invention, reference is now made tothe accompanying drawing, showing a preferred embodiment of theinvention, in which;

FIG. 1 is a longitudinal sectional view through a muffler embodying theinvention, taken on the line 11, of FIG. 2;

FIG. 2 is a transverse sectional view through the expansion barrel ofthe muffler, taken as on the line 2-2, in FIG. 1;

FIG. 3 is a transverse sectional view through the inlet portion of themufller, taken as on the line 33, FIG. 1;

FIG. 4 is a fragmentary section of one end portion of one of the tubularsections of expanded sheet metal with which the barrel of the muffler islined;

FIG. 5 is an enlarged, fragmentary elevation of a portion of a sheet ofexpanded sheet metal such as is used for lining the muffler;

FIG. 6 is a transverse section thereof, taken as on the line 66, FIG. 5;and

FIG. 7 is a small scale perspective view of the upper end portion of theexpansion barrel, showing the elbow with slotted underside.

Referring now more particularly to the embodiment of the inventionillustrated in the drawing, in which similar numerals refer to similarparts throughout, the mufiler comprises generally the expansion barrel 1formed of sheet metal of cylindrical shape and of any desired ornecessary length.

The mufller to which the invention pertains is especially adapted foruse upon trucks and the like, and for this purpose the expansion barrel1 is preferably located vertically on one side of the vehicle andextends to a point above the top of the cab thereof.

The lower end of the expansion barrel is closed by the wall 2 having acentral opening from which the cylindrical neck 3 extends downward. Theinlet pipe 4, of smaller diameter than the tubular neck 3, extendscentrally therethrough and into the lower end of the expansion barrel 1,the upper end of the inlet pipe being preferably outwardly flared, asindicated at 5.

This inlet pipe may be connected to the lower end portion of theexpansion barrel as by the spiders 6. A tube 7, of larger diameter thanthe neck 3, surrounds said neck and is closed at its lower end as at 8,and connected to the inlet pipe 4 as at 9. The upper end of the tube 7is spaced downwardly from the bottom wall 2 of the expansion barrel, andthe closed end 8 of the tube 7 is spaced downwardly from the lower endof the neck 3, as best shown in FIG. 1.

This provides a tortuous passage through which atmospheric air may enterthe inlet end of the expansion chamber in the direction of the arrowsshown in FIG. 1, or in like manner back pressure within the expansionbarrel may be released and passed outwardly from the expansion barrel ina direction opposite to said arrows.

The inlet pipe 4 may be connected to the neck 3 by spiders, as indicatedat 10 in FIG. 3, and in like manner the tube 7 may be connected to theneck 3 as by spiders 11, shown in said figure.

A principal feature of the invention is the provision of expanded sheetmetal lining within the expansion barrel of the mufiier. For thispurpose, a common and well known type of expanded sheet metal is used,of the type commonly used for metal lath and the like.

A fragmentary elevation of such expanded sheet metal, shownsubstantially full size, is illustrated in FIG. and a transverse sectiontherethrough is shown in FIG. 6. In these views it will be seen that theweb portions 12 of this expanded sheet metal are located at acute anglesto the normal plane of the expanded metal sheet.

Applicant takes advantage of this angular arrangement of the webportions in the expanded sheet metal to assist in breaking up soundwithin the mufller. In forming the lining for the expansion barrel, theexpanded sheet metal as shown in FIGS. 5 and 6 is preferably formed intotubular sections of such lengths that a plurality of such sectionslocated longitudinally end to end extend from one end of the expansionbarrel to the other.

Each of these tubular sections, as indicated at 13 and best shown inFIG. 4, has its opposite ends flared outwardly as at 14 forming annularflanges for contact with the inner Walls of the expansion barrel 1.

As best shown in FIG. 1, these tubular sections of expanded sheet metalare preferably oppositely arranged so that the angular Web portions 12of alternate tubular sections are oppositely disposed. In actualpractice, this has been found to assist in breaking up the sound of theexhaust gases within the expansion barrel.

As the exhaust gases are admitted to the lower end portion of theexpansion barrel from the inlet pipe 4, they will expand outwardly andupon contact with the lowermost section of expanded sheet metal, inwhich the Web portions 12 are angled upwardly and forwardly, will easilypass therethrough.

Upon contact with the next upper section of expanded sheet metal, inwhich the web portions 12 are rearwardly and downwardly angled, theexhaust gases upon contact therewith will be reflected back into thecentral portion of the expansion barrel, and so on throughout the lengthof the expansion barrel, thus tending to break up the sound.

Instead of providing only a single layer of expanded sheet metal liningwithin the expansion barrel, one or more additional tubular sections ofexpanded metal may surround each section 13, between the same and theinner Wall of the barrel, as indicated at 13a in FIGS. 1 and 2, thusincreasing the efiectiveness of the lining in breaking up the sound.

If desired, a lining 15 of expanded metal may be placed upon the bottomwall 2 of the expansion barrel. Also, if desired, one or more layers ofexpanded metal may be located between the inlet pipe 4 and the neck 3,as indicated at 16 in FIGS. 1 and 3, and between the neck 3 and the tube7, as indicated at 17 in said figures.

For the purpose of directing the exhaust gases away from the cab of thetruck, or other vehicle upon which the mufller is located, an elbow 19may be attached to the upper end of the expansion barrel 1, as bestshown in FIG. 7.

This elbow is preferably a 45 elbow, disposed rearwardly so as to directexhaust gases away from the cab. A longitudinally disposed slot oropening 20 is formed in the underside of the elbow to release backpressure at the upper end of the mufller. One or more layers of expandedsheet metal may line the interior of the elbow as indicated at 21.

From the above it will be obvious that a simple, inexpensive andeffective mufller is provided for trucks and the like, wherein the soundfrom the exhaust gases may be broken up and absorbed by contact ofexhaust gases with the expanded sheet metal lining arranged in sectionswith the angular web portions thereof alternately disposed in oppositedirections, and in which back pressure may be quickly and easilyreleased from the expansion barrel.

In the foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchwords are used for descriptive purposes herein and are intended to bebroadly construed.

Moreover, the embodiments of the improved construction illustrated anddescribed herein are by way of example, and the scope of the presentinvention is not limited to the exact details of construction.

Having now described the invention or discovery, the construction, theoperation, and use of preferred embodimerits thereof, and theadvantageous new and useful results obtained thereby; the new and usefulconstruction, and reasonable mechanical equivalents thereof obvious tothose skilled in the art, are set forth in the appended claims.

I claim:

1. A muffier comprising a tubular expansion barrel, an inlet pipe ofless diameter than the expansion barrel and located in the inlet end ofthe barrel, and a lining upon the inner walls of the expansion chambercomprising expanded sheet metal having angularly disposed web portions,said expanded sheet metal lining being formed of alternate tubularsections having the web portions oppositely disposed.

2. A muffler comprising a tubular expansion barrel, an inlet pipe ofless diameter than the expansion barrel and located in the inlet end ofthe barrel, and a lining upon the inner walls of the expansion chambercomprising expanded sheet metal having angularly disposed web portions,said expanded sheet metal lining being formed of alternate tubularsections having the web portions oppositely disposed, each tubularsection of expanded sheet metal having outwardly flared ends contactingthe inner wall-s of the barrel.

3. A mufiier comprising a tubular expansion barrel, an inlet pipe ofless diameter than the expansion barrel and located in the inlet end ofthe barrel, and a lining upon the inner walls of the expansion chambercomprising concentric layers of expanded sheet metal having angularlydisposed web portions, said expanded sheet metal lining being formed ofalternate tubular sections having the web portions oppositely disposed.

4. A muffler comprising a tubular expansion barrel open at its dischargeend and having an end wall at its inlet end, there being a centralopening in said end wall, a tubular neck extending outwardly from saidopening, an inlet pipe of less diameter than said tubular neck andlocated therethrough and into the expansion barrel, a tube of largerdiameter than said tubular neck and surrounding the same, and closuremeans for said tube spaced from the end of said tubular neck, forming atortuous path through which back pressure from the expansion barrel maypass between the inlet pipe and said tubular neck and between saidtubular neck and said tube.

5. A mufller comprising a tubular expansion barrel open at its dischargeend and having an end wall at its inlet end, there being a centralopening in said end wall, a tubular neck extending outwardly from saidopening, an inlet pipe of less diameter than said tubular neck andlocated therethrough and into the expansion barrel, 2. tube of largerdiameter than said tubular neck and surrounding the same, and closuremeans for said tube spaced from the end of said tubular neck, forming atortuous path through which back pressure from the expansion barrel maypass between the inlet pipe and said tubular neck and between saidtubular neck and said tube and expanded sheet metal linings upon theinteriors of said tubular neck and said tube.

6. A mufller comprising a tubular expansion barrel open at its dischargeend and having an end wall at its inlet end, there being a centralopening in said end wall,

a tubular neck extending outwardly from said opening, an inlet pipe ofless diameter than said tubular neck and located therethrough and intothe expansion bar-rel, a tube of larger diameter than said tubular neckand surrounding the same, and closure means for said tube spaced fromthe end of said tubular neck, forming a tortuous path through which backpressure from the expansion barrel may pass between the inlet pipe andsaid tubular neck and between said tubular neck and said tube, andlinings upon the interiors of said tubular neck and said tube, saidlinings comprising multiple layers of expanded sheet metal havingangularly disposed web portions alternately disposed in oppositedirections.

References Cited in the file of this patent UNITED STATES PATENTSFOREIGN PATENTS Germany Nov. 28, 1957

